diff --git a/cmd/audio-player/adpcm.js b/cmd/audio-player/adpcm.js
index c3424944..396f2b5a 100644
--- a/cmd/audio-player/adpcm.js
+++ b/cmd/audio-player/adpcm.js
@@ -93,8 +93,8 @@ function decodeSample(nibble) {
 function decode(b) {
     // Iterate over each chunk and decode it.
     let chunkLen;
-    var result = [];
-    for (var off = 0; off + headSize <= b.length; off += chunkLen) {
+    let result = [];
+    for (let off = 0; off + headSize <= b.length; off += chunkLen) {
         // Read length of chunk and check if whole chunk exists.
         chunkLen = bytesToInt32(b.slice(off, off + chunkLenSize))
         if (off + chunkLen > b.length) {
@@ -108,20 +108,20 @@ function decode(b) {
 
         result.push(...b.slice(off + chunkLenSize, off + chunkLenSize + byteDepth));
 
-        for (var i = off + headSize; i < off + chunkLen - b[off + chunkLenSize + 3]; i++) {
-            var twoNibs = b[i];
-            var nib2 = twoNibs >> 4;
-            var nib1 = (nib2 << 4) ^ twoNibs;
+        for (let i = off + headSize; i < off + chunkLen - b[off + chunkLenSize + 3]; i++) {
+            let twoNibs = b[i];
+            let nib2 = twoNibs >> 4;
+            let nib1 = (nib2 << 4) ^ twoNibs;
 
-            var sample1 = int16ToBytes(decodeSample(nib1));
+            let sample1 = int16ToBytes(decodeSample(nib1));
             result.push(...sample1);
 
-            var sample2 = int16ToBytes(decodeSample(nib2));
+            let sample2 = int16ToBytes(decodeSample(nib2));
             result.push(...sample2);
         }
         if (b[off + chunkLenSize + 3] == 1) {
-            var padNib = b[off + chunkLen - 1];
-            var sample = int16ToBytes(decodeSample(padNib));
+            let padNib = b[off + chunkLen - 1];
+            let sample = int16ToBytes(decodeSample(padNib));
             result.push(...sample);
         }
     }